I think I'll remove one of the blank keys instead.
Your choice, but you really should listen to what he's telling you, as it will be much easier. FYI the blank keys are used for other keymaps, so they might be blank on yours, but for keyboards used in other countries they'd have characters printed on them.
In any case, given your limited technical skill I'd suggest you might be better off paying the $27 (19 EUR?) for a brand new UK-layout keyboard from AmigaKit. That sounds like a heck of a deal to me, and there's videos on YouTube showing how to swap it out.